Field
Aspects of the present invention generally relate to an object detecting apparatus, an image capturing apparatus, a method for controlling an object detecting apparatus, and a storage medium.
Description of the Related Art
An image processing technique for detecting a specific object (a person, an animal, a specific object, etc.) from an image is known. For example, an image processing technique for detecting a human face as an object can be used in many fields, such as a TV conference, a man-machine interface, security, a monitoring system for tracking a human face, and image compression.
Digital cameras and digital video cameras detect, for example, a human face, from a captured image and implement exposure control and focus detection control based on the result of face detection. For the image processing technique for detecting a specific object from an image, various methods have been proposed. Most of the methods are based on pattern matching. One example is a method for clipping partial images at a plurality of different positions on an image and determining whether or not the partial images are images of a face area to detect a face area on the image. Whether the partial images are images of a face area or not can be determined by template matching or using an identifier that has learned the characteristics of a face by a learning method of a neural network.
Any of the methods generally calculate the degree of reliability indicating the degree of likelihood that the partial images are images of an object area on the basis of the patterns of the partial images and detect partial images whose degrees of reliability exceed a predetermined threshold value as images of the object area. Japanese Patent Laid-Open No. 2010-141847 discloses a method of storing the history of the degrees of reliability of detected areas and changing the number of detection times or the time until the object is detected on the basis of the degree of reliability.
However, if an object to be detected is present in a target image having large distortion, the object is significantly distorted. Thus, the method disclosed in Japanese Patent Laid-Open No. 2010-141847 may decrease the degree of reliability of the object in the significantly distorted area, thus making it impossible to perform determination of the detected object.